Abstract: A tag information selecting method variably sets a maximum distance for which a tag reader/writer is to make contactless communication with an electronic tag, and determines as a processing target each electronic tag that is separated by a distance shorter than or equal to the maximum distance from the tag reader/writer, of electronic tags located within a communicatable range of the tag reader/writer, and validates information read from and/or information to be written to each electronic tag that is determined as the processing target.

Abstract: Abnormality of a comparator is to be detected while it is assembled in a control apparatus. An output OUT of a comparator 4 is connected to a first analog data input port 13 in addition to an input port 11 of a microcomputer 6. A pin P1 as a signal input terminal of the comparator is connected to a second output port 15 capable of outputting an H or L microcomputer signal MO of the microcomputer and also to a second analog data input port 14. An abnormality judgment portion 9 of the microcomputer can detect abnormality due to failure of the comparator itself and failure of the peripheral devices on the basis of the output of the comparator during a normal operation, the comparator output when the microcomputer signal is outputted, and the comparator outputs before and after the output and stop of the microcomputer signal.

Abstract: Abnormality of a comparator is to be detected while it is assembled in a control apparatus. An output OUT of a comparator 4 is connected to a first analog data input port 13 in addition to an input port 11 of a microcomputer 6. A pin P1 as a signal input terminal of the comparator is connected to a second output port 15 capable of outputting an H or L microcomputer signal MO of the microcomputer and also to a second analog data input port 14. An abnormality judgment portion 9 of the microcomputer can detect abnormality due to failure of the comparator itself and failure of the peripheral devices on the basis of the output of the comparator during a normal operation, the comparator output when the microcomputer signal is outputted, and the comparator outputs before and after the output and stop of the microcomputer signal.

Abstract: In a microcomputer 10 including an output port 20 for outputting digital signals and an AD conversion register 18 for converting an analog voltage inputted to an AD input port 16 to a digital signal, the output port 20 and the AD input port 16 are directly connected. The output port 20 is allowed to selectively output H of a power source potential and L of a ground potential. The AD conversion register 18 is judged as being failed when any one of predetermined high order bits of the AD conversion register 18 is not 1 at the H output, or when any of one of the predetermined high order bits is not 0 at the L output. The digital conversion value of this AD conversion register 18 is not used. Thereby, existence/absence of failure of the AD conversion register is detected without using 2 channels for the AD input port.

Abstract: In the disclosure, MR sensors 6a and 6b for detecting the periodical angle position of rotating members rotating in conjunction with a steering wheel shaft are disposed in the vicinity of rotating members. These MR sensors are connected with a CPU 12, which makes the operation/processing of data from the MR sensors to calculate an absolute steering angle, including the indication of how many times the wheel has turned (periodicity). When the ignition key is turned off, the CPU 12 changes its operation mode into a stop mode of suspending said operation/processing, after storing the periodicity and the angle position &ggr; of the rotating members in a flash memory.

Abstract: In the disclosure, MR sensors 6a and 6b for detecting the periodical angle position of rotating members rotating in conjunction with a steering wheel shaft are disposed in the vicinity of rotating members. These MR sensors are connected with a CPU 12, which makes the operation/processing of data from the MR sensors to calculate an absolute steering angle, including the indication of how many times the wheel has turned (periodicity). When the ignition key is turned off, the CPU 12 changes its operation mode into a stop mode of suspending said operation/processing, after storing the periodicity and the angle position &ggr; of the rotating members in a flash memory.